If interning an instance of a string subclass, intern a real string object
with the same value instead. This ensures that a string (or string
subclass) object's ob_sinterned pointer is always a str (or NULL), and
that the dict of interned strings only has strs as keys.
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 8d9e81e..b029979 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1529,6 +1529,20 @@
verify(s.lower().__class__ is str)
verify(s.lower() == base)
+ s = madstring("x y")
+ verify(intern(s).__class__ is str)
+ verify(intern(s) is intern("x y"))
+ verify(intern(s) == "x y")
+
+ i = intern("y x")
+ s = madstring("y x")
+ verify(intern(s).__class__ is str)
+ verify(intern(s) is i)
+
+ s = madstring(i)
+ verify(intern(s).__class__ is str)
+ verify(intern(s) is i)
+
class madunicode(unicode):
_rev = None
def rev(self):